Selective Inhibitors of Histone Deacetylase 10 (HDAC-10)

2021 ◽  
Vol 28 ◽  
Author(s):  
Eftiola Pojani ◽  
Daniela Barlocco

: Histone acetylation balance is one epigenetic mechanism controlling gene expression associated with disease progression. It has been observed that histone deacetylase 10 (HDAC-10) isozyme contributes to the chemotherapy resistance; in addition, the poor clinical outcome observed in patients with aggressive solid tumors, such as neuroblastoma, has been associated with its overexpression. Moreover, HDAC-10 selective inhibition suppresses the autophagic response, thus providing an improved risk-benefit profile compared to cytotoxic cancer chemotherapy drugs. On these bases, HDAC-10 is becoming an emerging target for drug design. Due to the rapid progress in the development of next-generation HDAC inhibitors, this review article aims to provide an overview on novel selective or dual HDAC-8/10 inhibitors, as new leads for cancer chemotherapy, able to avoid the severe side-effects of several actual approved “pan” HDAC inhibitors. A literature search was conducted in MedLine, PubMed, Caplus, SciFinder Scholar databases from 2015 to the present. Since the disclosure that the HDAC-6 inhibitor Tubastatin A was able to bind HDAC-10 efficiently, several related analogues were synthesized and tested. Both tricyclic (25-30) and bicyclic (31-42) derivatives were considered. The best pharmacological profile was shown by 36 (HDAC-10 pIC50 = 8.4 and pIC50 towards Class I HDACs from 5.2–6.4). In parallel, based on the evidence that high levels of HDAC-8 are a marker of poor prognosis in neuroblastoma treatment, dual HDAC-8/10 inhibitors were designed. The hydroxamic acid TH34 (HDAC-8 and 10 IC50 = 1.9 µM and 7.7 µM, respectively) and the hybrid derivatives 46d, 46e and 46g were the most promising both in terms of potency and selectivity. Literature surveys indicate several structural requirements for inhibitory potency and selectivity towards HDAC-10, e.g., electrostatic and/or hydrogen bond interactions with E274 and complementarity to the P(E,A) CE motif helix.

2018 ◽  
Author(s):  
Magalie Géraldy ◽  
Michael Morgen ◽  
Peter Sehr ◽  
Raphael R. Steimbach ◽  
Johannes Ridinger ◽  
...  

The discovery of isozyme-selective histone deacetylase (HDAC) inhibitors is critical for understanding the biological functions of individual HDACs and for validating HDACs as clinical drug targets. The isozyme HDAC10 contributes to chemotherapy resistance via inhibition of autophagic flux and has recently been described to be a polyamine deacetylase, but no studies directed toward selective HDAC10 inhibitors have been published. Herein, we disclose that the use of two complementary ligand-displacement assays has revealed unexpectedly potent HDAC10 binding of tubastatin A, which has been previously described as a highly selective HDAC6 inhibitor. We synthesized a targeted selection of tubastatin A derivatives and found that a basic amine in the cap group was required for strong HDAC10, but not HDAC6, binding. Only potent HDAC10 binders mimicked HDAC10 knockdown by causing dose-dependent accumulation of acidic vesicles in the BE(2)-C neuroblastoma cell line. Docking of inhibitors into human HDAC10 homology models indicated that a hydrogen-bond between a basic cap group nitrogen and the HDAC10 gatekeeper residue Glu272 was responsible for potent HDAC10 binding. Taken together, the presented assays and homology models provide an optimal platform for the development of HDAC10-selective inhibitors, as exemplified with the tubastatin A scaffold.<br>


2018 ◽  
Author(s):  
Magalie Géraldy ◽  
Michael Morgen ◽  
Peter Sehr ◽  
Raphael R. Steimbach ◽  
Johannes Ridinger ◽  
...  

The discovery of isozyme-selective histone deacetylase (HDAC) inhibitors is critical for understanding the biological functions of individual HDACs and for validating HDACs as clinical drug targets. The isozyme HDAC10 contributes to chemotherapy resistance via inhibition of autophagic flux and has recently been described to be a polyamine deacetylase, but no studies directed toward selective HDAC10 inhibitors have been published. Herein, we disclose that the use of two complementary ligand-displacement assays has revealed unexpectedly potent HDAC10 binding of tubastatin A, which has been previously described as a highly selective HDAC6 inhibitor. We synthesized a targeted selection of tubastatin A derivatives and found that a basic amine in the cap group was required for strong HDAC10, but not HDAC6, binding. Only potent HDAC10 binders mimicked HDAC10 knockdown by causing dose-dependent accumulation of acidic vesicles in the BE(2)-C neuroblastoma cell line. Docking of inhibitors into human HDAC10 homology models indicated that a hydrogen-bond between a basic cap group nitrogen and the HDAC10 gatekeeper residue Glu272 was responsible for potent HDAC10 binding. Taken together, the presented assays and homology models provide an optimal platform for the development of HDAC10-selective inhibitors, as exemplified with the tubastatin A scaffold.<br>


2019 ◽  
Vol 20 (7) ◽  
pp. 1605 ◽  
Author(s):  
Jonathan Iaconelli ◽  
Lucius Xuan ◽  
Rakesh Karmacharya

Recent studies show that histone deacetylase 6 (HDAC6) has important roles in the human brain, especially in the context of a number of nervous system disorders. Animal models of neurodevelopmental, neurodegenerative, and neuropsychiatric disorders show that HDAC6 modulates important biological processes relevant to disease biology. Pan-selective histone deacetylase (HDAC) inhibitors had been studied in animal behavioral assays and shown to induce synaptogenesis in rodent neuronal cultures. While most studies of HDACs in the nervous system have focused on class I HDACs located in the nucleus (e.g., HDACs 1,2,3), recent findings in rodent models suggest that the cytoplasmic class IIb HDAC, HDAC6, plays an important role in regulating mood-related behaviors. Human studies suggest a significant role for synaptic dysfunction in the prefrontal cortex (PFC) and hippocampus in depression. Studies of HDAC inhibitors (HDACi) in human neuronal cells show that HDAC6 inhibitors (HDAC6i) increase the acetylation of specific lysine residues in proteins involved in synaptogenesis. This has led to the hypothesis that HDAC6i may modulate synaptic biology not through effects on the acetylation of histones, but by regulating acetylation of non-histone proteins.


2019 ◽  
Vol 19 (4) ◽  
pp. 546-556
Author(s):  
Duong T. Anh ◽  
Nguyen T. Thuan ◽  
Pham-The Hai ◽  
Le-Thi-Thu Huong ◽  
Nguyen T.K. Yen ◽  
...  

Background: Histone Deacetylase (HDAC) inhibitors represent an extensive class of targeted anticancer agents. Among the most explored structure moieties, hydroxybenzamides and hydroxypropenamides have been demonstrated to have potential HDAC inhibitory effects. Several compounds of these structural classes have been approved for clinical uses to treat different types of cancer, such as givinostat (ITF2357) and belinostat (PXD-101). Aims: This study aims at developing novel HDAC inhibitors bearing N-hydroxybenzamides and Nhydroxypropenamides scaffolds with potential cytotoxicity against different cancer cell lines. Methods: Two new series of N-hydroxybenzamides and N-hydroxypropenamides analogues (4a-j, 6a-j) designed based on the structural features of nexturastat A, AR-42, and PXD-101, were synthesized and evaluated for HDAC inhibitory potency as well as cytotoxicity against three human cancer cell lines (SW620 (colorectal adenocarcinoma), PC3 (prostate adenocarcinoma), and NCI-H23 (adenocarcinoma, non-small cell lung cancer). Molecular simulations were finally carried out to gain more insight into the structure-activity relationships. Results: It was found that the N-hydroxypropenamides (6a-e) displayed very good HDAC inhibitory potency and cytotoxicity. Various compounds, e.g. 6a-e, especially compound 6e, were up to 5-fold more potent than suberanilohydroxamic acid (SAHA) in terms of cytotoxicity. These compounds also comparably inhibited HDACs with IC50 values in the sub-micromolar range. Docking experiments showed that these compounds bound to HDAC2 at the enzyme active binding site with the same binding mode of SAHA, but with higher binding affinities. Conclusions: The two series of N-hydroxybenzamides and N-hydroxypropenamides designed and synthesized were potential HDAC inhibitors and antitumor agents. Further development of these compounds should be warranted.


2020 ◽  
Vol 27 (36) ◽  
pp. 6099-6111 ◽  
Author(s):  
Dimitrios Schizas ◽  
Aikaterini Mastoraki ◽  
Leon Naar ◽  
Diamantis I. Tsilimigras ◽  
Ioannis Katsaros ◽  
...  

Chemotherapy resistance is a rising concern in Gastric Cancer (GC) and has led to the investigation of various cellular compounds. Α functional equilibrium of histone acetylation and deacetylation was discovered in all cells, regulated by Histone Acetyltransferases and Deacetylases (HDACs), controlling chromatin coiling status and changing gene expression appropriately. In accordance with recent research, this equilibrium can be dysregulated in cancer cells aiding in the process of carcinogenesis and tumor progression by altering histone and non-histone proteins affecting gene expression, cell cycle control, differentiation, and apoptosis in various malignancies. In addition, increased HDAC expression in GC cells has been associated with increased stage, tumor invasion, nodal metastases, increased distant metastatic potential, and decreased overall survival. HDAC inhibitors could be used as treatment regimens for GC patients and could develop important synergistic interactions with chemotherapy drugs. The aim of this article is to review the molecular identity and mechanism of action of HDAC inhibitors, as well as highlight their potential utility as anti-cancer agents in GC.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2900-2900 ◽  
Author(s):  
Matthew C. Stubbs ◽  
Won-Il Kim ◽  
Tina Davis ◽  
Jun Qi ◽  
James Bradner ◽  
...  

Abstract Abstract 2900 Histone deacetylase inhibitors (HDACi) have emerged as potent anticancer agents, and could open the door for future epigenetic therapies. As our understanding of the importance of epigenetic histone modifications in B-cell acute lymphoblastic leukemia (B-ALL) increases, we hypothesized that HDACi could potentially be a useful therapeutic option. The pan-HDAC inhibitor LAQ824 (Novartis) was toxic to B-ALLs in low nM concentrations in vitro, and treated cells had increased p21 and DNA damage response as indicated by increased γH2A.X protein levels. Additionally, the related compound panobinostat (Novartis) reduced leukemic burden from B-ALL patient samples in primary xenograft models, indicating that pan-HDAC inhibition is a putative B-ALL therapeutic option. To determine HDAC isoform-specific effects, we used a high throughput assay that exposed B-ALL cell lines to a panel of HDAC inhibitors. This screen indicated that tubacin, an HDAC6 specific inhibitor, cannot inhibit B-ALL cell growth within a dose range where HDAC6 is the only HDAC targeted. This finding was further validated using another HDAC6 specific inhibitor, WT-161. The screen also indicated that benzimide compounds such as MGCD-0103 (MethylGene) and MS-275 (Entinostat, Syndax) which only target class I HDACs (HDAC1-3) effectively inhibited growth in the cell lines. These data indicate that inhibiting the class I HDACs is sufficient to suppress B-ALL cell line growth. To determine which HDACs are necessary for cell viability, we lentivirally introduced isoform-specific shRNAs into our ALL cell lines. Knockdown of HDAC1 or HDAC2 resulted in p21 induction, slowed growth rate and resulted in a modest increase in apoptosis. Knockdown of HDAC3 lead to increased p21 and γH2A.X protein levels, along with induction of apoptosis, closely mimicking the results of pan-HDAC inhibitor treatment of the cells. Although depletion of HDAC3 had a more immediate impact on B-ALL viability by comparison to HDAC1/2, concerns about the contribution of HDAC3 inhibition to toxicity led us to further investigate whether specific inhibition of HDAC1/2 might be efficacious in B-ALL. Treatment of B-ALL cells with Merck 60, a tool compound with selectivity for HDAC1/2, was efficacious against was effective against B-ALL lines in the low to mid nM range. The kinetics of growth suppression were slower with this compound than with the pan-HDAC inhibitors. Using this compound, the ALL lines required 72 hours of exposure before cell growth was diminished, and apoptosis ensued. This may be due to the increased time necessary to accumulate acetylated histone marks as observable by western blot (18 hours for Merck 60 vs. 2–4 hours for LAQ824). Increased levels of p21 and γH2A.X were also observed. Interestingly, AML cell lines were much less sensitive to the HDAC1/2 specific inhibitor than were the B-ALL lines (roughly 5–10 fold), whereas pan-HDAC inhibitors were equally effective against AML and ALL. Additionally, non-hematopoietic tumor derived cell lines were insensitive to Merck 60, with EC50 values exceeding 20μM. Our findings indicate that pan-HDAC and class I specific HDAC inhibitors are possible therapeutic options for B-ALL. In contrast to most other cancer cell types studied, selective inhibition of HDAC1 and HDAC2 was sufficient to induce apoptosis in B-ALL lines. Together, these results suggest that small molecules specifically targeting HDAC1/2 may have therapeutic utility in B-ALL, and may provide improved therapeutic index by comparison to pan-HDAC or class I HDAC inhibitors that also target HDAC3. Disclosures: No relevant conflicts of interest to declare.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3974
Author(s):  
A. Daryl Ariawan ◽  
Flora Mansour ◽  
Nicole Richardson ◽  
Mohan Bhadbhade ◽  
Junming Ho ◽  
...  

Histone deacetylase enzymes (HDACs) are potential targets for the treatment of cancer and other diseases, but it is challenging to design isoform-selective agents. In this work, we created new analogs of two established but non-selective HDAC inhibitors. We decorated the central linker chains of the molecules with specifically positioned fluorine atoms in order to control the molecular conformations. The fluorinated analogs were screened against a panel of 11 HDAC isoforms, and minor differences in isoform selectivity patterns were observed.


2021 ◽  
Vol 22 (11) ◽  
pp. 5516
Author(s):  
Qiting Zhang ◽  
Ziyan Wang ◽  
Xinyuan Chen ◽  
Haoxiang Qiu ◽  
Yifan Gu ◽  
...  

Epigenetic therapy using histone deacetylase (HDAC) inhibitors has become an attractive project in new drug development. However, DNA methylation and histone acetylation are important epigenetic ways to regulate the occurrence and development of leukemia. Given previous studies, N-(2-aminophenyl)benzamide acridine (8a), as a histone deacetylase 1 (HDAC1) inhibitor, induces apoptosis and shows significant anti-proliferative activity against histiocytic lymphoma U937 cells. HDAC1 plays a role in the nucleus, which we confirmed by finding that 8a entered the nucleus. Subsequently, we verified that 8a mainly passes through the endogenous (mitochondrial) pathway to induce cell apoptosis. From the protein interaction data, we found that 8a also affected the expression of DNA methyltransferase 1 (DNMT1). Therefore, an experiment was performed to assess the binding of 8a to DNMT1 at the molecular and cellular levels. We found that the binding strength of 8a to DNMT1 enhanced in a dose-dependent manner. Additionally, 8a inhibits the expression of DNMT1 mRNA and its protein. These findings suggested that the anti-proliferative and pro-apoptotic activities of 8a against leukemia cells were achieved by targeting HDAC1 and DNMT1.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1505
Author(s):  
Kyle N. Hearn ◽  
Trent D. Ashton ◽  
Rameshwor Acharya ◽  
Zikai Feng ◽  
Nuri Gueven ◽  
...  

Methodology to access fluorescent 3-amido-1,8-naphthalimides using direct Buchwald–Hartwig amidation is described. The protocol was successfully used to couple a number of substrates (including an alkylamide, an arylamide, a lactam and a carbamate) to 3-bromo-1,8-naphthalimide in good yield. To further exemplify the approach, a set of scriptaid analogues with amide substituents at the 3-position were prepared. The new compounds were more potent than scriptaid at a number of histone deacetylase (HDAC) isoforms including HDAC6. Activity was further confirmed in a whole cell tubulin deacetylation assay where the inhibitors were more active than the established HDAC6 selective inhibitor Tubastatin. The optical properties of these new, highly active, compounds make them amenable to cellular imaging studies and theranostic applications.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xingjing Guo ◽  
Dan Chen ◽  
Shuhong An ◽  
Zhaojin Wang

Calcitonin gene-related peptide (CGRP) is a mediator of microglial activation at the transcriptional level. The involvement of the epigenetic mechanism in this process is largely undefined. Histone deacetylase (HDAC)1/2 are considered important epigenetic regulators of gene expression in activated microglia. In this study, we examined the effect of CGRP on HDAC2-mediated gene transcription in microglial cells through the chromatin immunoprecipitation sequencing (ChIP-seq) method. Immunofluorescence analysis showed that mouse microglial cells (BV2) expressed CGRP receptor components. Treatment of microglia with CGRP increased HDAC2 protein expression. ChIP-seq data indicated that CGRP remarkably altered promoter enrichments of HDAC2 in microglial cells. We identified 1271 gene promoters, whose HDAC2 enrichments are significantly altered in microglia after CGRP treatment, including 1181 upregulating genes and 90 downregulating genes. Bioinformatics analyses showed that HDAC2-enriched genes were mainly associated with immune- and inflammation-related pathways, such as nitric oxide synthase (NOS) biosynthetic process, retinoic acid-inducible gene- (RIG-) like receptor signaling pathway, and nuclear factor kappa B (NF-κB) signaling pathway. The expression of these key pathways (NOS, RIG-I, and NF-κB) were further verified by Western blot. Taken together, our findings suggest that genes with differential HDAC2 enrichments induced by CGRP function in diverse cellular pathways and many are involved in immune and inflammatory responses.


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